The CA map for diagnosis at MCC is shown in Figure 1
using an exceedance probability threshold of 0.90. In all, 54 out
of 134 counties in Virginia were included in the CA. The CA
is centered in Richmond, as expected, and consists of a contiguous
set of counties, along with the Eastern Shore of Virginia
counties Northampton and Accomack. We also mapped the
exceedance probabilities estimated from the Bayesian logistic
regression model (Fig. 2) to show that the definition of the CA
is not heavily dependent on the exceedance probability threshold
value. The number of counties in the estimated CA using
the exceedance probability thresholds of 0.80, 0.85, and 0.95
were 57, 54, and 53, respectively. For the following results, we
used the threshold of 0.90.